Fire alarm gong apparatus



y 3- V J. M. MOG'UINNESS 2,318,005

FIRE ALARM GONG APPARATUS Filed Oct. 21, 1941 Patented May 4, 1943 UNITED sures eras? OFFIC FIRE ALARM GONG APPARATUS James M. McGuinness, Worcester, Mass. Application October 21, 1941, Serial No. 415,925

4 Claims.

This invention relates to a fire alarm gong apparatus and more particularly to a fire alarm gong and support therefor in which a fusible plug acts as a switch closing-preventing means until such time as the plug melts, whereupon mechanism is operated to sound the gong.

Objects of the invention includes the provision of a gong having a single support adapted to be attached to a Wall, bracket, or the like, the support being hollow and containing a slidably mounted spring-pressed metallic plunger which is held in inoperative position away from a pair of electric contacts by means of a fusible plug which engages the plunger and holds it in retracted position against the action of the spring until sufiicient heat is applied to melt the plug and thereby permit the spring to urge the plunger into engagement with the electric contacts, thereby closing an electric circuit to an electrically operated clapper vibrating device or buzzer.

Other objects of the invention include the provision of a gong having a central aperture therethrough, an open-ended support extending through the aperture, and a plug in the open end of the support, said plug being visible from the front side of the gong and being operable to maintain a circuit closing device in open position.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing wherein Fig. l is a View in front elevation of the fire alarm gong device with part of the gong broken away;

Fig. 2 is an enlarged central sectional view of the gong and its support showing the parts in circuit-open position;

Fig. 3 is a view similar to Fig. 2, but showing the parts in circuit-closed position;

Fig. 4 is a fragmentary view of a, wall bracket on which the gong support may be mounted; and

Fig. 5 is a view in section through the wall bracket of Fig. 4 and showing the gong support mounted thereon.

The reference character It) indicates a bracket or the like in the form of a plate which is adapted to be mounted on a wall, ceiling, or other support by means of screws or other fasteners and having a flange [2 adapted to space the plate In a short distance from the wall, etc. Plate I0 is provided with a keyhole slot M for a purpose to be described. An electrically operated vibratory device l6 for a clapper element [8 may be mounted in any desired position on the late Hi, this device being of conventional construction. Y

,A cylindrical hollow member 2i! which may be made of porcelain or the like material is pro-. vided at one end with a closed solid portion in an exterior surface of which a, headed pin 22 is set. The head of pin 22 is spaced from the end surface of the hollow member 20 a distance corresponding to the thickness of plate I!) and it will be seen that the head of the pin may be inserted in the keyhole slot I4 so as to mount the member and well known 20 normal to plate Ill, as is clearly shown in Fig.

5, so that the head of the pin engages the wall and the end surface of member 20 engages the ward thrust on a cylindrical metal plunger 28,

the latter conforming in diameter to and being slidably mounted in the chamber. A pair of U-shaped electrical contacts 38 extend through appropriate radial apertures in member 20 adjacent but spaced from the open end thereof. One leg of each contact is secured tothe member 20 in any desired or convenient manner, and the other leg is free to pivot within the confines of its aperture. It will be particularly noted that the free ends of the contacts extend into the chamber in member 20 in position to be engaged by the metal plunger 28 when the latter is urged outwardly thereof by the spring 26.

At the end of member 20 opposite pin 22 the member is open and is provided with a radially outwardly extending flange 32 and an inwardly extending rib 34. At the base of the flange, member 20 is externally screw threaded as at 36 to receive and support the gong 38 by means of a central aperture in the latter.

It will be seen from the above description that the gong 38 and member 20 may be secured together in fixed relation and that the member 20 with gong attached may be mounted on the wall bracket. By this means member 20 becomes the sole support for the gong and is adapted to be mounted on the wall bracket in desired position with relation to the clapper l8, so that when the latter is vibrated the gong will be sounded.

A wax plug in the form of a truncated cone is shown at 40, there being a peripheral groove 42 in the plug adjacent its wider end. This plug is so porportioned as to be capable of being thrust into the open end of the hollow chamber in mem her 20 and by reason of groove 42 and rib 34 the plug will be held against accidental discharge and vibration. Also the wider end of the plug may be indented by the inner edge of the opening of the hollow chamber, so as to become fixed or cemented in position, due to its waxy nature. When the plug is so located its narrow end engages the metal plunger 28 and holds it in spaced condition relative to contacts 30, against the action of spring 26, but it will be clear that if heat is applied to the plug it will melt and will either run down away from the opening in member 20 or will be forced outwardly by reason of spring 26, whereupon the metal plunger 28 will be urged towards and will bridge the contacts and close the circuit through a battery 44 and leads 46 to apply electric energy to the device It so that the gong will be sounded.

It will be noted that the action of the plunger will cause the free leg of each contact 30 to be pivoted down or outwardly into contact with the fixed leg thereof, so that the plunger cannot bend the contacts and will be stopped thereby. Hence the contacts prevent any .dislodgment' of the gong, thus avoiding the necessity of removing or disturbing any of the alarm parts whatever. Also an alarm as herein disclosed may be easily recognized by reason of the fact that the plug 40 is clearly visible from the front of the gong and may be'colored so as to more easily distinguish it from the porcelain flange 32 and the gong 38. From the front of the device the plug and flange resemble the bulls-eye in a target.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. In a device o f the class described, the combination of a gong having a normally visible side surface with a support for said gong, circuit closing means housed in said support, a fusible plug arranged to normally maintain said circuit closing means in open position, and means for sounding the gong upon melting of the plug and consequent closing of the circuit, said support extending through the gong, and said plug being mounted in the support so as to be visible at said surface. 1

2. A device as recited in claim 1 wherein said support is hollow, a pair of electric contacts extending into the hollow portion of said support, a plunger in said hollow portion, said plug being adapted to extend between said contacts into engagement with said plunger to normally maintain it in spaced condition relative to said contacts, and said plug being replaceable from the visible side of the gong.

3. In a device of the class described, the combination of a gong having means forming a central aperture therethrough, a hollow support having a closed end and an open end and extending through said aperture and supporting the gong adjacent said open end, means at the closed end to mount said support on an object, a circuit closing device in said support, a fusible plug enterable through the open end of the support and providing means normally to prevent closing of said circuit closing device, a gong-sounding device and electrical. means to actuate the latter, said circuit closing device being in circuit with said gong-sounding device.

4. In a device of the class described, the combination of a gong having means forming a central aperture therethrough, a porcelain or the like hollow cylindrical support extending through said aperture, means securing said gong to the support, said support having aclosed end and an open end, a flange at said open end, a wax plug or the like in said open end, a pair of electric contacts in said support, a slidable metallic plunger in said support, said plug normally holding said plunger spaced from said contacts, a gong sounding device, and a circuit forthe latter including said contacts.

JAMES M. MCGUINNESS. 

